This application is based upon and claims the benefit of priority of Japanese Patent Applications No. 2001-85954 filed on Mar. 24, 2001 and No. 2001-106260 filed on Apr. 4, 2001, the contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to windshield wiper device mounting a washer nozzle and a washer hose, in particular, suitable for cleaning a windshield glass of a vehicle.
2. Description of Related Art
Vehicle windshield wiper device for wiping a windshield glass has a wiper arm and a wiper blade attached to the wiper arm.
The wiper arm has an arm head whose one end is fixed to a pivot shaft, a retainer whose one end is pivotally connected via a holding pin to the other end of the arm head to enable a given angle rotation about an axis of the pin, a spring retained between the arm head and the retainer for resiliently biasing the retainer toward the windshield glass, and an arm piece fixed to the other end of the retainer. An end of the arm piece terminates in a U shaped hook for connecting with the wiper blade. The wiper blade has a blade rubber for contacting and wiping the windshield glass and a plurality of levers holding the blade rubber.
When the vehicle windshield wiper device is operated, the wiper arm and the wiper blade make well known reciprocating and rotating movements for removing raindrops on the windshield glass.
Further, in a vehicle having a larger windshield glass in which a washer nozzle mounted on a hood of the vehicle is located relatively far from an aimed point of the windshield glass which washer liquid from the washer nozzle strikes, the washer nozzle is mounted on the wiper arm or wiper blade for delivering the washer liquid to the aimed point without fail, as shown in JP-U-61-97059 which discloses the windshield wiper device with a washer nozzle and the washer fluid hose that are attached to the wiper arm.
According to the windshield wiper device proposed in JP-U-61-97059, a wiper head is provided on a backside thereof with a straight-line groove and a washer liquid hose is fitted in the groove. This structure has an advantage that the hose is properly routed through the groove and is out of sight from the user.
However, the hose mounting structure mentioned above has a drawback that, if the hose is pulled longitudinally by a force applied from outside or generated according to the rotation of the wiper arm, the hose is prone to slip out of the groove since the hose is deformed to take the shortest route in a longitudinal direction of the wiper arm. Therefore, even if the groove is provided, a clip or clips as extra parts for holding the hose in place become necessary to prevent the hose from slipping out of the groove. The use of the extra parts and extra assembly steps thereof are costly.
An object of the present invention is to provide a windshield wiper device in which a washer hose for delivering washer liquid to a washer nozzle mounted on a wiper arm or a wiper blade is firmly held by an arm head without using extra parts and with fewer assembly steps.
Another object of the present invention is to provide an apparatus of manufacturing the arm head for firmly holding the hose with less operating time and manufacturing cost.
To achieve the former object mentioned above, the windshield wiper device has a pivot shaft, a wiper arm, a wiper blade, a washer nozzle and a washer hose. The wiper arm has an arm head whose one end is fixed to the pivot shaft to rotate about an axis of the pivot shaft, a retainer whose one end is pivotally connected via a holding pin to the other end of the arm head to enable a given angle rotation about an axis of the pin, an arm piece whose one end is fixed to the other end of the retainer and whose the other end is pivotally connected with the wiper blade. The wiper hose is arranged along the arm head and the retainer for connecting with the washer nozzle to deliver washer liquid thereto.
With the arm head mentioned above, the arm head is provided with an undulated groove defined by groove sidewalls having at least first and second hill portions that protrude opposite to each other in a width direction of the arm head and are located adjacent to each other in a longitudinal direction thereof. A length between tops of the first and second hill portions in the width direction of the arm head is shorter than a diameter of the hose, or, preferably, is less than zero.
The hose accommodated in the groove comes in frictional engagement with peripheries of the tops of the first and second hill portions when a force pulls the hose in a longitudinal direction of the arm head. Accordingly, this groove shape is effective to prevent the hose from slipping out of the groove in a longitudinal direction of the arm head. Further, as the force to pull the hose is larger, the frictional resistance between the hose and the hill portions is larger so that the hose is firmly held in the groove.
It is preferable that the groove sidewalls further have a first dale portion that are opposed to the first hill portion in the width direction of the arm head and continuously adjacent to the second hill portion in the longitudinal direction thereof.
It is more preferable that the groove side walls further have a third hill portion protruding oppositely to the first hill portion in a width direction of the arm head and being located continuously adjacent to the first dale portion on a side opposite to the second hill portion in the longitudinal direction thereof.
Preferably, at least one of the tops of the first, second and third hill portions, preferably, each of the tops of the second and third hill portions, is provided at an upper surface thereof with a projection protruding in the width direction of the arm head so as to overhang the groove. The projection or projections prevent the hose inserted into the groove from coming off the groove. In particular, when a force acts on the hose in a longitudinal direction of the groove, the hose is fitted deep into the groove so that the hose is more deeply held in the groove.
The arm head is generally manufactured by injection molding in such a manner that molten metal or resin is injected into split die. The split die is separable into two pieces in opposite directions and parallel to an axial direction of a hole into which the pivot shaft is inserted and fixed. The groove just behind the projection constitutes an undercut portion so that, to form the groove just behind the projection, a slide die moving perpendicularly to a moving direction of the split die is required.
It is preferable that the slide die is located on a side of a periphery of the arm head, a distance from which in the width direction thereof to one of the tops of the first and second hill portions is shorter than that to the other of the tops of the first and second hill portions. Accordingly, a moving stroke of the slide die is shorter so that a time required for manufacturing the arm head is shorter.